SLUSBV9C March 2014  – February 2016


  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Pin Configuration and Functions
  6. Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Power-On Reset
    6. 6.6  2.5-V LDO Regulator
    7. 6.7 Charger Attachment and Removal Detection
    8. 6.8 CHG and DSG FET Drive
    9. 6.9 Overvoltage Protection (OVP)
    10. 6.10Undervoltage Protection (UVP)
    11. 6.11Overcurrent in Discharge (OCD)
    12. 6.12Overcurrent in Charge (OCC)
    13. 6.13Short-Circuit in Discharge (SCD)
    14. 6.14Low Voltage Charging
    15. 6.15Internal Temperature Sensor Characteristics
    16. 6.16High-Frequency Oscillator
    17. 6.17Low-Frequency Oscillator
    18. 6.18Integrating ADC (Coulomb Counter) Characteristics
    19. 6.19ADC (Temperature and Cell Voltage) Characteristics
    20. 6.20Data Flash Memory Characteristics
    21. 6.21Timing Requirements
    22. 6.22Typical Characteristics
  7. Detailed Description
    1. 7.1Overview
    2. 7.2Functional Block Diagram
    3. 7.3Feature Description
      1. 7.3.1Configuration
      2. 7.3.2Fuel Gauging
      3. 7.3.3Power Modes
        1. Mode
        2. Mode
        3. Mode
      4. 7.3.4Li-Ion Battery Protector Description
        1. NFET Charge and Discharge FET Drive
        2. Configuration
    4. 7.4Device Functional Modes
      1. 7.4.1Operating Modes
        1. Mode
        2. Mode
        3. Mode
        4. CHARGE Mode
        5. WAIT Mode
          1. SHUTDOWN State
        6. VOLTAGE CHARGING State
      2. 7.4.2Firmware Control of Protector
      4. 7.4.4Wake-Up Comparator
    5. 7.5Battery Parameter Measurements
      1. 7.5.1Charge and Discharge Counting
      2. 7.5.2Voltage
      3. 7.5.3Current
      4. 7.5.4Auto-Calibration
      5. 7.5.5Temperature
    6. 7.6Communications
      1. 7.6.1HDQ Single-Pin Serial Interface
      2. 7.6.2I2C Interface
        1. Time Out
        2. Command Waiting Time
    7. 7.7Standard Data Commands
      1. 7.7.1Control(): 0x00 and 0x01
    8. 7.8Extended Data Commands
  8. Application and Implementation
    1. 8.1Application Information
    2. 8.2Typical Applications
      1. 8.2.1Pack-Side, Single-Cell Li-Ion Fuel Gauge and Protector
      2. 8.2.2Design Requirements
      3. 8.2.3Detailed Design Procedure
        1. BAT Voltage Sense Input
        2. SRP and SRN Current Sense Inputs
        3. Sense Resistor Selection
        4. TS Temperature Sense Input
        5. Thermistor Selection
        6. VPWR Power Supply Input Filtering
        7. REG25 LDO Output Filtering
        8. Communication Interface Lines
        9. PACKP Voltage Sense Input
        10. and DSG Charge Pump Voltage Outputs
        11. Selection
        12. ESD Protection Components
      4. 8.2.4Application Curves
  9. Power Supply Recommendation
    1. 9.1Power Supply Decoupling
  10. 10Layout
    1. 10.1Layout Guidelines
      1. 10.1.1Li-Ion Cell Connections
      2. 10.1.2Sense Resistor Connections
      3. 10.1.3Thermistor Connections
      4. 10.1.4FET Connections
      5. 10.1.5ESD Component Connections
      6. 10.1.6High Current and Low Current Path Separation
    2. 10.2Layout Example
  11. 11Device and Documentation Support
    1. 11.1Documentation Support
      1. 11.1.1Related Documentation
    2. 11.2Community Resources
    3. 11.3Trademarks
    4. 11.4Electrostatic Discharge Caution
    5. 11.5Glossary
  12. 12Mechanical, Packaging, and Orderable Information

1 Features

  • Battery Fuel Gauge and Protector for Single-Cell Li-Ion Applications
  • Microcontroller Peripheral Provides:
    • Precision 16-Bit, High-Side Coulomb Counter with Low-Value Sense Resistor
      (5 mΩ to 20 mΩ)
    • External and Internal Temperature Sensors for Battery Temperature Reporting
    • Lifetime and Current Data Logging
    • 64 Bytes of Non-Volatile Scratch Pad Flash
    • SHA-1 Authentication Capability
  • Battery Fuel Gauging Based on Patented Impedance Track™ Technology
    • Models Battery Discharge Curve for Accurate Time-To-Empty Predictions
    • Automatically Adjusts for Aging, Self-Discharge, and Temperature- and Rate-Induced Effects on Battery
  • Integrated High-side NMOS Protection FET Drive
  • Hardware-based Safety and Protection:
    • Overvoltage (OVP)
    • Undervoltage (UVP)
    • Overcurrent in Charge (OCC)
    • Overcurrent in Discharge (OCD)
    • Short-Circuit in Discharge (SCD)
  • I2C™ and HDQ Interface Formats for Communication with Host System
  • Ultra-Compact, 15-Ball NanoFree™ DSBGA

2 Applications

  • Smartphones
  • Tablets
  • Handheld Terminals
  • MP3 and Multimedia Players
  • Portable Gaming

3 Description

The Texas Instruments bq27742-G1 is a fuel gauge for single-cell Li-Ion battery packs that uses patented Impedance Track™ technology to deliver rate-, temperature-, and aging-compensated predictions of remaining battery capacity and system runtime with highest accuracy. The device also includes a fully integrated high-side protector that eliminates the need for a separate Li-Ion protection circuit and provides a full suite of high-accuracy fault detections for overvoltage, undervoltage, overcurrent in charge, overcurrent in discharge, and short-circuit in discharge conditions. The hardware protection functions offer built-in data flash-based programmability, allowing simple reconfiguration of existing devices for varying end equipment needs.

The fuel gauge provides information such as remaining battery capacity (mAh), state-of-charge (%), runtime to empty (minutes), voltage (mV), current (mA), and temperature (°C), as well as recording vital parameters throughout the lifetime of the battery. The device also supports interrupts to the host to indicate detection of a variety of important battery conditions to the system.

The DSBGA is a 15-ball package (2.78 mm × 1.96 mm) that is ideal for space-constrained applications.

Device Information(1)

BQ27742YZFR-G1YZF (15)2.78 mm × 1.96 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

Simplified Schematic

bq27742-G1 Simple_Sch_Scale.gif

4 Revision History

Changes from B Revision (August 2015) to C Revision

Changes from A Revision (December 2014) to B Revision